This invention is an improvement upon vacuum filler equipment of the type described in U.S. Pat. No. 2,543,788 issued Mar. 6, 1951 to M. W. Loveland, in Battinich U.S. Pat. No. 2,903,023 and in Loveland U.S. Pat. No. 3,990,487 issued on Nov. 9, 1976. The filling head is similar to and an improvement upon those shown in the latter patent.
Most present packing methods for tuna and other fish products use drip-filling or spray methods for filling the liquids used in packing them. These liquids normally are low-viscosity, relatively fluid vegetable oils or water which tend to be centrifically flung from the vacuum filling heads at machine positions where the filling head is not in sealing engagement with the container being filled. The drip and spray methods result in a substantial amount of filling oil, for example, actually being lost or that which can be recovered must be recycled or discarded if too contaminated.
The vacuum filler of this invention is particularly useful for filling steel cans containing more-or-less compressible and tacky material, such as tuna fish or salmon, with the non-viscous liquids normally used for packing those products. In attempting to modify equipment such as that shown in Loveland Pat. Nos. 2,543,788 and 3,990,487 for tuna fish service, for example, applicants have found that the packed tuna fish tended to cling to the generally concave surface of the kind of displacement pad or disc illustrated in those patents. The adhered particulate matter was subsequently drawn into and contaminated the filler vacuum system.